### Harmonic Series

$\displaystyle {\begin{alignedat}{8}1&+{\frac {1}{2}}&&+\Big({\frac {1}{3}}&&+{\frac {1}{4}}\Big)&&+\Big({\frac {1}{5}}&&+{\frac {1}{6}}&&+{\frac {1}{7}}&&+{\frac {1}{8}}\Big)&&+\Big({\frac {1}{9}}&&+\cdots \\ {}\geq 1&+{\frac {1}{2}}&&+\Big({\frac {1}{\color {red}{\mathbf {4} }}}&&+{\frac {1}{4}}\Big)&&+\Big({\frac {1}{\color {red}{\mathbf {8} }}}&&+{\frac {1}{\color {red}{\mathbf {8} }}}&&+{\frac {1}{\color {red}{\mathbf {8} }}}&&+{\frac {1}{8}}\Big)&&+\Big({\frac {1}{\color {red}{\mathbf {16} }}}&&+\cdots \\ {}= 1&+{\frac {1}{2}}&& +\ \ {\frac {1}{2}}&& && +\ \ {\frac {1}{2}}&& && && &&+\ \ \ {\frac {1}{2}}&&+\cdots =\infty\end{alignedat}}$ Mercator series $\displaystyle \ln 2 = 1-{\frac {1}{2}}+{\frac {1}{3}}-{\frac {1}{4}}+{\frac {1}{5}}-\cdots$ Leibniz Series for $